Electric lamp and socket



Feb. 21, 1961 F, MICHAEL r 2,972,699

ELECTRIC LAMP AND SOCKET Filed Feb. 12, 1958 2 Sheets-Sheet 1 FIMHWFHA/E 1961 J. F. MICHAEL EI'AL 2,97

ELECTRIC LAMP AND SOCKET Filed Feb. 12, 1958 2 Sheets-Sheet 2 2,972,699ELECTRIC LAMP AND SOCKET Jacob F. Michael, Cresskill, George W. Caplis,Preakness, and Harry A. Holden, Caldwell, N.J., and George C. Lennox,Southbury, (Bonn, assignors to Westinghouse Electric Corporation, EastPittsburgh, Pa., a corporation of Pennsylvania Filed Feb. 12, 1958, Ser.No. 714,730

14 Claims. (Cl. 313318) This invention relates generally to lightingapparatus and, more particularly, to an improved prefocus type electriclamp and socket for equipment that requires a precisely oriented sourceof light such as picture pro,- jectors and the like.

As is well-known, the light source used in picture projection equipmentmust not only be concentrated and of uniform brightness but must beprecisely located With respect to the focal axis of the optical systemin order to achieve maximum illumination of the screen and picturebrightness. Heretofore, positioning of the light source was generallyaccomplished by means of a springbiased socket and a flanged prefocustype base adapted to resiliently interlock one with the other and thusanchor the lamp in the desired location within the projector. Morerecently, a plug-in or radio type base and socket combination has beenmarketed which facilitates tosorne extent the orientation of the lightsource during lamp manufacture. In both these arrangements, however,,considerable pressure or torque had to be applied to the lamp topositively seat it within the socket. Due to the recessed position ofthe lamp in the projector housing, only the top portion of the lamp bulbcan be grasped thereby making the seemingly simple manipulation requiredto insert and properly seat lamps of this type rather diflicult toaccomplish. Even this inconvenience, however, was considered tolerablecompared to the patience and dexterity required on the part of the lampuser to remove the lamp from such a fixture, particularly in thoseinstances where the lamp failed while in operation and the bulb wasstill hot. In addition, the prior art base and socket structures reliedon surface or line contact between their respective mating elements toeffect the desired indexing and prefocusing actions and on the strengthand acumen of the lamp user to insure that the members were positivelyseated one against the other.

It is accordingly the general object of the present invention to obviatethe foregoing deficiencies of the prior art structures.

Another object of the invention is to provide an improved couplingarrangement for positioningland maintaining an electrical device inprecise predetermined spatial and operative relation with the fixture inwhich it is used.

Another object of the invention is to provide an proved prefocus typelamp and socket for devices such as projectors or thelike that requireaccurately-positiqned light sources.

Still another and more specific object of ,theinvention is the provisionof means for conveniently locking a projection lamp or similarlightsource in precise positive alignment with the focal axis of an opticalsystem and then releasing it for easy withdrawal from its position ofuse.

A further object ofthe "invention is to provide a socket for aprojection type electric lamp which will precisely United States PatentF 2,972,699 Patented Feb. 21, 1961 and positively index the lamp intoits position of use and also facilitate its replacement.

' Another object of this invention is the provision of a projection typelamp and socket combination which can be simply and permanently lockedin precise prefocused alignment and when thus assembled have a shorteroverall length than conventional type structures heretofore used.

The foregoing objects, and others which will become obvious to thoseskilled in the art as the description proceeds, are achieved byproviding a base and socket of such construction that the lamp orsimilar device may be freely inserted into the socket and then by meansof a rotatable locking member forcibly and permanently coupled inprecisely spaced and operative relation with said socket. In the case ofan incandescent projection lamp, the light source or filament plane isinitially oriented angularly with respect to the optical axis of theprojector and the lamp terminals aligned with the socket contacts bymeans of a depending plug or post on the base which registers with andis received by a suitably contoured aperture provided at the bottom ofthe socket. The locking member when actuated is designed to engage aplurality of pin-like extensions provided on the basal portion of thelamp, which extensions register with and are received by suitablerecesses in the socket,

and in cooperation therewith produce a cam-like action that firmly seatsthe lamp within the socket at a predetermined reference plane andpressures the lamp terminals into positive mating engagement with thesocket contacts. In addition, one of the aforementioned recesses is sooriented as to provide a forward stop which, in

cooperation with a selected oneof th'e base pins, serves to positivelyand precisely index the lamp angularly into its position of use relativeto the focal axis of the projectors optical system when the lockingmember is actuated. The base and socket are also contoured to seat oneagainst the other in point contact rather than surface or line contactas in the prior art structures thereby obviating any possibility of thelamp being tilted or otherwise forced from its aligned position byirregularities or other defects in those portions of the socketheretofore utilized as the contacting surface. Thus, Vertical andangular registration of the lamp with the socket is not onlyconveniently and automatically effected by means of the locking memberbut is accomplished with a degree of accuracy and reliability heretoforeunattainable.

A better understanding of the invention may be had by referring to theaccompanying drawing wherein:

Fig. 1 is an elevational view of an incandescent projection lampincorporating this invention;

Fig. 2 is a plan view of the basal end portion of the lamp shown in Fig.1 illustrating the angular relationship between the filament plane, basepins, center post, and

the lamp terminals;

'Fig. 3 is an exploded view in perspective and on an enlarged scaleof'the sealed-in end portion of the lamp, the terminal caps and thebasemember according to the invention; v

Fig. 4 is an enlargedsectional view through the basal end portion ofthelamp along the line lV-IV of Fig. 2, in the direction of the arrows;

,Fig. 5 is an elevational fragmentary view of the lamp shown in Fig. 1locked in assembled relation with the socket member of'this invention,the recessed part of the lamp .being shown in dotted outline'toillustrate the pressure contact effected between the lamp and socketterminals; h

I Fig. 6 is a sectional View th rough the basal end portion of the socketed lamp along the line VI-Vlof Fig. 5,

inthe direction of the arrows,"illustr atingithe spatal reia;

Pa :3 tionship of the base and socket elements when the locking memberis in its closed position;

Fig. 7 is a plan view of the socket member shown in Fig. and correspondsto the view shown in Fig. 6, except that the locking member is disposedin its open or lamp-receiving position to illustrate the manner in whichit registers with the recesses in the body portion of the socket;

Fig. 8 is a side view in elevation of the socket member shown in Fig. 7;

Fig. 9 is a cross-sectional view through the socket along the lineIX--IX of Fig. 8, in the direction of the arrows;

Fig. 10 is a plan view of the bottom of the socket shown in Fig. 7;

Fig. 11 is a cross-sectional view through the socket member along theline XI-XI of Fig. 8, in the direction of the arrows;

Fig. 12 is a view of the socket member corresponding to Fig. 7 but on anenlarged scale and shows the lamp in its position of use therein, thelocking member being omitted except for the handle portion thereof andparts of the lamp being broken away to more clearly illustrate thedisposition of and the interaction between the various base and socketelements when the lamp and socket are locked in operative relation; and

Fig. 13 is an exploded view of the socket assembly in perspectiveillustrating in greater detail the structural fea tures of the variouselements according to this invention, particularly the interior of theinsulating body portion.

While the base and socket members and manner of indexing and lockingthem together in prefocused alignment in accordance With the principlesof this invention may be advantageously employed to precisely orient andcouple various types of devices or components, the invention isespecially adapted for use in conjunction with an'electric lamp'of theprefocus type used in picture projectors and hence has been soillustrated and will be so described.

Turning now to the drawing, in Fig. 1 there is shown an incandescentprojection lamp 14 which embodies the base structure of this invention.The lamp 14 comprises, in general, a tubular light-transmitting envelope16 having a constricted basal end portion 18 which is terminated on aplane transverse and preferably substantially perpendicular to the lampaxis by means of an end wall 19 (see Figs. 3 and 4) and provided with abase member 40. A pair of spaced main leads 22 and 26 sealed through theend wall 19 support a suitable concentrated light source such as asectionally-coiled planar filament 32 (of either the well-knownmonoplane or biplane type, for example) in parallel relation with thelamp axis and at a predetermined distance f from the outer peripheraledge of the base member 40. The closed or domed end of the envelope 16may be provided with an opaque coating 17 of suitable high temperaturematerial such as ceramic paint or the like to prevent the emission ofstray light, as is known in the art. Lamps of this character may bedesigned either for vertical or horizontal burning by properlypositioning and supporting the filament, the lamp 14 here illustratedbeing of the latter type as evidenced by the location of the well-knowncollector and heat-deflecting screen 23 above the filament 32, as viewedin Fig. 1.

As illustrated more particularly in Fig. 4, the out-er surface of theend wall 19 is preferablyof such character as to define a plane which issubstantially normal to the lamp and filament axes and spaced apredetermined distance f from the center of the filament 32. Inaccordance with standard lamp-making practice, the envelope 16 isevacuated through an exhaust tubulation which is subsequently tipped offto form the usual protruding seal tip 21.

In addition to the main leads 22 and 26, a pair of clipped or auxiliaryleads 24 and 28 are also sealed through the end wall 19 radiallyequidistant from said main leads, as shown in Figs. 2, 3 and 6. Thefirst of 4 said auxiliary leads is interiorly connected to the main lead26 through a fuse lead 30 (Fig. 3) having the usual tubular glass shield31 slipped thereover to prevent sputtering and safely extinguish the aregenerated when the lamp fails. The remaining auxiliary lead 28 is leftunconnected and serves as a dummy lead to equalize the thermal stressesimparted to the glass during sealing thereby minimizing the danger ofcracks and generally facilitating the fabrication of the lamp. Thus, thefilament 32 is connected across the main lead 22 and the auxiliary lead24 which leads may be termed currentcarrying leads and in accordancewith the invention have their outer ends inserted into and secured torivetlike contact caps 36 and 38 respectively to provide a pair of lampterminals having enlarged and substantially flat end surfaces. The basemember 40 is provided with an axially depending center post 46 and isadapted to be received by and coupled to a socket member 50 in themanner illustrated in Figs. 5, 6 and 12, which socket member ishereinafter described in more detail.

The essence of this invention resides in the construction of the baseand socket members 40 and 5t respectively and in the manner with whichthey cooperate to position and lock the lamp 14 in precise prefocusedalignment and facilitate its replacement.

For example, as shown in Figs. 1 to 5 and more particularly in Fig. 3,the base member 40 comprises a cylindrically hollow metal shell orcup-like member having a V tance from the bottom wall 41 (see Fig. 4).

bottom wall 41 provided with an appendage or plug such as an axiallydepending center post 46 which may be noncircular in cross-section orkeyed as by means of a longitudinally-extending rib 47. The bottom wall41 of the base member 40 is substantially normal to the center post 46and is suitably embossed to provide radiallyextending strengthening ribs42 and a protruding peripheral lip or bead 44 which defines a plane thatis substantially parallel to and spaced a predetermined dis- The basemember 40 is provided with a plurality of laterally-extending elementssuch as pins 48a, 48b, and 480 which may be formed by extruding theshell material or fabricated separately and staked or otherwise fastenedthereto, as shown in Fig. 4, so as to be radially spaced therearound atpredetermined distances. Preferably, the pins are spaced atapproximately equal distances from each other and disposed in a commonplane which is substantially perpendicular to the plane containing thefilament 32, as illustrated in Figs. 1 to 6.

The bottom wall 41 of the base shell is provided with circular apertures43 appropriately spaced and dimensioned to accommodate and register withcorrespondingly shaped lead bosses 20 formed from the glass of the end7; wall 19 around the main leads 22 and 26 and auxiliary leads 24 and28. Thus, by properly aligning the base member 40 with the sealed-inlamp during the biasing operation, the pins 48a, 48b and 48c may beconveniently and accurately located angularly with respect to the planecontaining the filament 32 so as to elfect the relationship illustratedin the drawing and hereinafter described. This arrangement also servesto more positively insulate the base member 40 from the leads thusobviating the possibility of a short circuit occurring during operationof the lamp 14.

' particularly in Fig. 12. The base member 40 when thus disposed is intelescope relation with the constricted end portion 18 and is securedthereto as' by means of suitable basing cement 45 in the usual manner.As far as the contact caps .36 and 38 are concerned, they may be mountedon the said current-carrying leads either before or after the basemember 40 has been attached to the envelope 16, as desired, so thattheir fiat end surfaces are disposed transverse and preferablysubstantially normal to the axis of the lamp 14, as shown in Figs. 1, 4and 5. Thus, by virtue of the positive seating engagement effectedbetween the bottom wall 41 of the base member 40 and the end wall 19 ofthe lamp envelope 16, the plane defined by the bead 44 is located apredetermined distance 1 (see Figs. 1, 4 and 5) from the center of thefilament 32 and disposed substantially perpendicular to the planethereof. In addition, both the key-rib 47 of the center post 46 and thepin 48a-are so oriented as to be displaced a predetermined angle fromthe plane containing the filament 32, as for example 45 from a linenormal to said plane as shown in Figs. 2, 6 and 12. By virtue of itsprecise predetermined angular relation with respect to the filamentplane, the pin 48a may be defined as a reference pin and will be sodesignated in the description which follows.

The present invention also provides a novel socket construction and modeof indexing the lamp into its' position of use and retaining it in suchposition, which features will now be described. As shown in Figs. 7through 11 and more particularly in Fig. 13, the socket member 50according to this invention comprises an insulating body 52 ofcylindrical configuration having a locking member 72 rotatably securedto its upper face 70 by suitable retaining means such as an annularcollar 82. The insulating body 52, as viewed in Fig. 13, is exteriorlycontoured to provide a central section 53 terminated by a top portion 54and a bottom portion 55 of reduced diameter. 54 is defined by aperipheral shoulder 56 which is substantially parallel to the upper face70 of said insulating body, as viewed in Fig. 13, and spaced apredetermined distance therefrom so as to provide a seat for the annularcollar 82. The annular collar 82 may be fabricated from a sleeve 84 ofsuitable metal and is of such width longitudinally that when firmlyseated against the shoulder 56 the clearance between a set of integralradially-spaced cleat-like elements or tongues 86, which tonguesprotrude radially inward from the upper edge of said sleeve, and theupper face 79 of'the insulating body 52 is slightly greater than thethickness of the material from which the locking member 72 isfabricated. Thus, when the sleeve 84 is secured to the projectorhousing, as by a pair of integrally-formed and apertured lugs 88, it ispressed against the shoulder 56 thereby firmly clamping the socketassembly 50 in its position of use within the projector but providingsufficient clearance between the tongues 8'6 and upper face 70 to permitthe locking member 72 interposed therebetween to be rotated.

As shown in Figs. 7 to 11 and 13, the central section 53 and the bottomportionSS of the insulating body 52 are divided interiorly along adiametric plane by a partition 64 into a pair of symmetrical chambers orcavities 65 of arcuate configuration which serve to receive a pair oflaterally-extending leaf-like contact elements 68 of resilientconductive material embedded in the central section 53 and to providemeans for ventilating and cooling the socket member 50. The end portionsof said contact elements 68 within the cavities 65 are enlarged andgenerally circular, as shown in Figs. 7 and to 12, whereas the oppositeends thereof project beyond the walls of the insulating body 52 thusproviding a cantilever contact assembly and rigidly anchored socketterminals69. The enlarged end portions of the socket contact elements 68are, accordingly, resiliently depressible with;.respect to theinsulating body 52 which construction permits the lamp terminals '36 andY38 to be pressured into eint-im-ate surfaceengagement with saidsocket;.con-

'tacts-whenthelamp l s-is locked in its position of use The inward edgedthe top portion 1 6 within the socket member 50 as hereinafterdescribed.

The central portion of the partition 64 is enlarged to providesufficient material to define a cylindrical aperture 66 .and a key-waydimensioned to freely receive the keyed =cente-r post 46 of the basemember 40. The central section 53 of the insulating body 52 isterminated interiorly to provide an annular platform 60 from which threeradially-spaced convex knobs or ribs 62 protrude (:see Fig, 5 and moreparticularly Figs. 7, 9 and 11 through 1.3)., the :tops of said ribsbeing disposed to define a plane that is substantially perpendicular tothe axis of the socket member 50 and spaced a predetermined distancefrom the bottom face of the insulating body 52, as viewed in Figs. 5, 9and 13. The partition 64 is also terminated "in the same plane. asv thesaid central section 53 of the insulating body 52so as not to interferewith the free entry and seating of the lamp '14. Insofar as thesocketmember 50 is mounted and positioned in the projector by clamping theinsulating body 52 to the projector housing with the retaining collar82, the aforementioned plane defined by the ribs 62 determines thespatial relation of the filament 32 (when the lamp 14 is disposed in itsposition of use ,in said socket member) with the optical system of theprojector in a vertical direction, or in a horizontal direction if thelamp is thus oriented within the projector.

The upper portion 54 of the insulating body 52 is interiorly contouredto provide axially-extending rectangular recesses 58 disposed toregister with and freely accommodate the pins 48a, 48b and 480 when thelamp -14 .is properly oriented and is of such diameter that it willfreely but snugly receive the base member '40 so that when said lamp isinserted intothe socket member 50 ashereinafter described, the bead 44at the peripheral edge of said base member will abut against theribs 62thereby positively seating the lamp at the aforementioned plane definedby;,said ribs. The ribs 62 thus provide a reference plane for the lamp14 and accurately position the filament 32 a predetermined distance ffrom such plane (see Figs. 5 and 9) thereby automatically effecting thevertical (or horizontal) alignment of the filament with respect to thefocal axis of the projector optical system. An axially-extending edge ofthe recess 58 that receives the reference pin 48a is precisely orientedangularly to provide a shoulder 59 which functions as a forward stop forthe aforesaid reference pin 48a during the socketing operation ashereinafter described.

The locking member 72, as here shown (particularly in Fig. 13), maycomprise a lever-like element having a ring portion 74 and a handleportion 76 fabricated as by stamping from suitable sheet metal ofrelatively high stiffness, as for example nickel-plated iron or thelike. Such ring portion 74 is of the same diameter and width as the topface of the insulating body 52 and is slit and sprung upwardly, asviewed in Fig. 13, at selected points along its inner periphery toprovide three radiallyspaced arcuate leaves or fingers 80. The freeendsof said fingers are bent sharply away from the ring portion 74 andclipped leaving three inner peripheral slots 78 spaced to register withthe base pins 48a, 48b and 48c. The top face 70 ofthe insulating body 52is substantially parallel to and spaced from the aforementionedfreference plane a distance approximately equal to the distanceseparating said pins from the bead 44 at the periphery of the basemember 40. Thus, when the locking member 72 is assembled with theinsulating body 52 and retaining collar 82 as above-described, the ringportion 74 is held inslidable relation with the top face 70 (see Figs. 8and 9 permitting. the inner peripheral slots 78'to be aligned with ordisplaced from the recesses 58 in the said insulating body' by rotatablyshiftingthe protruding handle portion 72 andyin turn, saidlocking memherin the' proper direction. The locking mernber 72.,as assembled isoriented toabut against a selected one of the tongues 86rand when sodisposedhaveits peripheral Y I slots 78 in registry with the recesses 58in the insulating body 52 thus permitting the free insertion of the lamp14. The locking member 72 is thus shiftable through a predeterminedangle between closed and lamp-receiving or opened positions as shown inFigs. 6 and 7 respectively.

In assembling the lamp 14 with the socket member 50, the locking member72 is first shifted to its open or lamp-receiving position shown in Fig.7 thereby aligning the inner peripheral slots 78 with rectangularrecesses 58 in the insulating body 52 as stated above. The basal endportion of the lamp 14 is then inserted into the socket member 50 andthe lamp rotated until the keyed center post 46 registers with theaperture inthe partition 64, said center post being purposely madelonger than the protruding portions of the leads (see Figs. 1 and 4) andthe rib 47 to rotatably engage the aperture 66 before the pins 48a, 48band 48c contact the locking member 72 and thus serve as aguide plug. Inorder to prevent the center post 46 from accidently contacting a part ofthe projector during or after lamp insertion, the bottom portion 55 ofthe insulating body 52 is of sufiicient depth to enable the partition 64to enclose said center post in its entirety.

With the lamp 14 thus oriented, the base pins 48a, 48b and 48c willautomatically be aligned with the inner peripheral slots 78 in thelocking member 72 and with the recesses 58 in the insulating body 52thereby roughly orienting the filament 32 with respect to the opticalaxis of the projector. The lamp 14 is then freely inserted into saidinsulating body until the bead 44 of the base member 40 abuts againstthe ribs 62. The locking member 72 is then shifted toward its closedposition shown in Fig. 6 whereupon the fingers 80 engage and ride overthe pins 48a, 48b and 480 effecting a cam-like action therewith andsimultaneously imparting a downward axial thrust and torque to the lamp14. The lamp 14 is thus forced axially into the socket member 50 andseated firmly against the ribs 62 and is simultaneously rotated withinsaid socket until the reference pin 48a strikes and seats against theabove-mentioned forward shoulder or stop 59 defined by thecorrespondingly located recess 58, as illustrated in Fig, 12. Thefingers 80 are so designed that this condition is reached before thelocking member 72 is shifted through an angular distance greater thanthe length of said fingers thus permitting sufficient pressure to beapplied to the handle portion 76 to produce a binding action betweensaid pins and the locking member 72 capable of permanently clamping thelamp 14 and socket member 50 in operative relation.

As shown in Fig. 5, the resultant axial pressure produced by thecam-like action of the fingers 80 on the pins 48a, 48b and 480 firmlyseats the bead 44 of the base member 40 in point contact with the ribs62 thus positively indexing the lamp 14 at the reference plane in thesocket member 50 and precisely locating the filament 32 a predetermineddistance 1; therefrom. The axial thrust also forces the enlarged endsurfaces of the lamp terminal caps 36 and 38 into mating and wipingengagement with the enlarged end portions of the socket contact elements68 thereby not only insuring positive electrical connection butresiliently depressing said elements and effecting a pressure contactbetween the lamp 14 and socket 50 over a considerable area. Insofar asthe primary purpose of the center post 46 is to coaxially align the lamp14 with the projectors optical system and with the socket member 56during the initial phase of insertion and roughly orient, so to speak,the filament plane with respect to the optical axis, it is proportionedto be slightly undersize with respect to the aperture 66 provided in thepartition 64 to insure free insertion of the lamp into the socket. Theresultant play between the center post 46 and the partition 64 and thepins 48a, 48b and 48c within their respective recesses 58 permits thelamp 14 and said pins to move angularly with respect to the socketmember 50 so that when the lamp is forcibly rotated upon actuation ofthe locking member 72 as above-described, only the reference pin 48aseats against the forward stop 59 defined by the correspondingly locatedrecess 58. Thus, the lamp 14 and socket member 50 are not onlyaccurately oriented axially and longitudinally with respect to eachother and the projec'tors optical system, but are angularly indexed andaligned one with the other by positive means and with a degree ofprecision heretofore unattainable.

Removal of the lamp 14 from the socket member 50 is achieved accordingto the invention by shifting the handle portion 76 of the locking member72 in the reverse direction until it strikes the edge of the tongue 86and is disposed in its open position shown in Fig. 7. As a result of thebinding interaction between the fingers 80 and the base pins 48a, 48band 48c, the lamp 14 is rotated within the socket member 50 unseatingthe reference pin 4811 from the stop 59 whereupon the upward thrust ofthe heretofore depressed socket contact elements 68 resiliently ejectthe lamp 14 partially out of the socket member 50 thereby automaticallyconditioning it for withdrawal and enabling it merely to be lifted outof the socket member 50 and the projector.

One of the significant advantages afforded by the base and socketconstruction of this invention over the prior art structures is thesubstantial reduction in the overall length of the lamp and socketcombination achieved by the telescopic relationship, so to speak, of theconstricted basal end portion 18 of the envelope 16, the base member 40and the socket member 50 when the aforesaid components are assembled andcoupled in operative relation. For example, the overall length of a 500watt projection lamp having a bulb 1 /2 inches in diameter whenfabricated and locked in its position of use within its socket accordingto this invention is about 4 inches whereas conventional type lamps withstandard bases and sockets measure about 7 inches in overall length.This reduction in the bulk of the lamp and socket unit enables theprojectors to be proportionately reduced in size and weight withoutsacrificing either lightgenerating capacity or efificiency of operation.

' It will be apparent from the foregoing that the objects of theinvention have been achieved insofar. as a lamp and socket combinationhas been provided which is not only very compact but capable of beingsimply and conveniently assembled in precise prefocused alignment andpositive electrical contact. In addition, the socket member is sodesigned that replacement of the lamp can be very conveniently andeasily accomplished regardless of its condition or location within theprojector.

While a preferred embodiment of the invention has been described indetail by way of illustration and example for purposes of clarity andunderstanding in accordance with the patent statutes, it is understoodthat various changes and modifications may be made without departingfrom the spirit and scope of the invention.

We claim:

1. A socket for a projection type lamp or the like comprising, a bodymember open and interiorl-y contoured at one end to freely receive thebasal end portion of said lamp, and locking means movably secured tosaid body member and rotatable about the axis thereof dis? posed whenactuated and said lamp is inserted into said body member, to engage andapply an axial thrust to said lamp of suflicient magnitude to forciblydepress the basal end portion thereof into and against said body memberand lock said lamp in operative relation with said socket.

2. A socket for a projection type lamp or the like comprising, a bodymember open end interiorly contoured at one end to freely butregisterably receive the basal end portion of said lamp and define areference plane therefor, and locking means movably secured to saidbodymember and rotatable about the axis thereof enemas '9 disposed, whenactuated and said lamp is insertedinto said body member, to engage andcontinuously apply an axial thrust 'to said lamp of "sufficientmagnitude to forcibly depress said'lamp intosaid body member against'thepart thereof that defines the aforesaid reference plane and lock-it insuch position.

3. .A socket fora projection type electric lamp or the like having abasal end portion with-at least one laterallyextending element, saidsocket comprising a'body member open and interiorly contoured "at oneend to freely and registerably receive the basal end portion of saidlamp and laterally-extendingelement thereat, -and locking means carriedby said body member, said locking means comprising a movable member thatis "rotatable about the axis of said body'memb'er and disposed,whenactuated and said lamp is placed into said body member, to engage theaforesaid "laterally-extending element and eifect a .camdike actiontherewithsuch that said'lamp is axially thrust into and against saidbody member and locked in operative relationwith said'isocket. j

4. Asocket for a projection type electric lamp or the like having a baseat one end provided with:a laterallyextending element, said socket"comprising a body of insulating material interiorly contoured at oneend to freely receive said .base and laterally-extendingelement anddefine a reference plane for. said lamp, and locking means carried bysaid insulating body, said locking means comprising a movable lockingmember secured to the lamp'receiving end of said insulating body androtatable about the axis thereof between open and closed positions, saidlocking member when in its open position being disposed topermit thefree insertion of said base and laterally-extending element into saidinsulating body and, upon displacement toward its closed position, beingadapted by virtue of its configuration and rotational movement to engagesaid laterally-extending element and effect a cam like actiontherewith'thatimpants an axial thrust .to said lamp of sufficientmagnitude to forcibly depress it into said insulating bodyagainst'thepant thereof that defines the aforesaid reference plane andlock it in-su-chposition and in operative relation withsaid socket.

5. A socket for a projection type electric lamp or the like having abasal end portion from which one terminal extends, said socketcomprising a body member interiorly contoured at one end to freelyreceive the basal end portion of said lamp and terminal thereat,insulated contact means .in said body member disposed to register andelectrically connect with said terminal when said lamp is operativelydisposed in said socket, and a locking member movably secured .to.theJamp-receiVin'g end of said body memberand.rotatablelabout the axisthereof between open and closed positions, isaid locking memberwhenin'its .openposition beingdisposed to permit the free insertion ofthe basal .end and terminal portionsof said lamp into said body memberand, upon displacement toward its closed position,-being adapted byvirtueof its configuration and rotational movement to engage the basalend portionof said .lampand in cooperation therewith effecta cam-likeaction that applies an axial "thrust to said lamp of sufiicientmagnitude-to forcibly depress it into and against said body member andsimultaneously press said" lamp terminalagainst said contact means, andthen lock said lamp and terminal in such position.

6. A socket for a projection type electric lamp or the like having abasal end portion from which two terminals axially extend, each of saidterminals having enlarged substantially fiat end surfaces disposed in aplane transverse to the lamp axis, said socket comprising a body ofinsulating material interiorly contoured at one end to freely receivethe basal end portion of said lamp and terminals thereat, a pair ofresiliently depressible con tact elements in said insulating bodydisposed to engage the enlarged flat end surfaces of the aforesaid lamptermiv,

nals when said lamp is disposed in operative relation in said socket,and an annular locking member slidably secured to thelamp receiving endof said insulating'body and rotatable about the axis thereof betweenopen and closed positions, said locking member when in itsopen positionbeing disposed to permitfree passage of the basal end'portionofsaid lampand terminals thereat into said insulatingbody, and upon displacementtoward :its closed-position, being adapted by virtue of itsconfiguration and rotational movement to engage and apply an axialthrust to said lamp of sufficient magnitude to forcibly depress it intoand against said insulating body and simultaneouslypress the fiatends-of the lamp terminals against said =contactelement-sand then looksaid lamp and terminals in such position.

"7. A socket "for aprojection type electric lamp or the like havingagenerally'cylindrical base at one end provided'with a plurality ofradially-spacedlaterally-extendingpinsfarrdfan axially-extending plugmember of noncircul'ar 'cross section, said socket comprising a body ofinsulating materialopen'and interiorly contoured at one end to freely'receivesaid base and having recesses at and extendingaxially inward'from its inner peripheral edge disposed to registerablybut freelyreceive said pins, means infsaid' insulating body for registerably butfreely receivingsaid'plug member, an axially-extending edge of aselectedone 'ofttherecessesin said insulating body being preciselylocated angularly and adapted thereby to con stiute a stopfor acorrespondingly-located reference pin 'onsaid'baseand controllably limitthe'rotative movement between said insulating body and lamp in apredetermined direction, and a locking member slidably secured to'thelamp -receivingend of said insulating body and rotatable about the axisthereof between open and closed positions,

. said locking member having a ring portion and a handle portion, saidring portion having substantially the same diameter as and being alignedwith the lamp-receiving end'ofsaid insulating body, a pluralityof pairedfinger like'elements and slots in the inner periphery of-saidringportion spaced so that said slots are aligned with the recesses insaidirrsulating body, when said locking member is in its open position,and are'rotatably displaced through a predetermined angle in theaforesaid predetermined direction when said locking member is shifted toits closed position, said finger-like elements being located to engagethe pins on the base of said lamp, when the latter is placed intothesocket and said locking member is shifted from open to closed position,and slidably cooperate therewith to produce a cam-like action thatsimultaneously imparts a torque and an axial thrust to said lamp thatforcibly depresses it into and against said insulating body and seatsthe aforesaid reference pin against the the stop defined 'bythe-edge ofthe preselected one of said recesses.

8. In combination, a projection type lamp or similar device having abasal end portion provided with gr'ippable means, .anda socketcomprising a body member interiorly contouredat one end to freelyreceive the basal end por tion of. said'lamp and having a movablelocking member thereat that isrotatable about the axis of said bodymember and disposed when actuated to engage said grippable means incam-like fashion, saidlamp being inserted in said body member, and saidlocking member being actuated and engaging said grippable means, wherebysaid lamp by virtue of the axial pressure exerted thereon bysaidlockingmember is forcibly depressed into and simultaneously seatedagainst said body member and locked in operative relation with saidsocket.

9. In combination, a projection type electric lamp or similar devicehaving a basal end portion with a grippable element, and a socketcomprising a body member interiorly contoured at one end to freelyreceive the basal end portion of said lamp and grippable element anddefine a reference plane for said lamp, the basal end portion of saidlamp being inserted into said body member and said grippable, elementbeing engaged in cam-like fashion by a movable locking member carried bysaid body member, said locking member being rotatable about the axis ofsaid body member and, in conjunction with said engaged grippableelement, applying an axial thrust to said lamp that seats it againstsaid body member at the afore said reference plane and looks it inpredetermined relation axially with said socket. 10. In combination, aprojection type electric lamp or similar device having a basal endportion with at least one grippable element, and a socket comprising abody of insulating material contoured at one end to freely andregi-sterably receive said basal end portion and grippable element andhaving a movable locking member that is rotatable about the axis of saidinsulating body anddisposed when actuated to engage said grippableelement in cam-like fashion and thereby apply an axial thrust to saidlamp, platform means in said insulating body defining a seat and anaxial reference plane for said lamp, said lamp being inserted into saidsocket and said locking member being actuated and in engagement withsaid grippable element, whereby said lamp is forcibly depressed intosaid insulating body and simultaneously seated against said platformmeans and locked in predetermined relation axially with said socket. 711. In combination, a projection type electric lamp or similar devicehaving a generally cylindrical base provided with at least onelaterally-extending element, and a socket comprising a body ofinsulating material open and contoured at one end to freely receive saidbase and having a recess in its inner peripheral wall extending axiallyfrom its lamp-receiving end and disposed to freely and registerablyreceive said laterally-extending element, a rotatable locking memberfastened to the lamp-receiving end of said insulating body and adaptedwhen actuated to engage said laterally-extending element in cam likefashion and thereby impart an axial thrust to said lamp, a platform insaid insulating body conformed and disposed respectively to engage anddefine a reference plane for said lamp, said lamp being inserted intosaid insulating body and said locking member being actuated and inengagement With said laterally-extending element, whereby said lamp isforcibly depressed into said insulating body and simultaneously seatedagainst said platform and locked in predetermined relation axially withsaid socket. 12. In combination, a projection type electric lamp orsimilar device having a basal end portion provided with at least oneaxially-extending terminal and at least one laterally-extending pin, anda socket comprising a body of insulating material open and interiorlycontoured at one end to freely accommodate the basal end portion of saidlamp and terminal and registerably receive said pin, said lamp beinginserted into said socket and said pin being engaged in carn-likefashion by a movable locking member that is carried by said insulatingbody and is rotatable about the axis thereof, whereby said lamp isforcibly depressed axially into said insulating body and locked inseated engagementtherewith, and said lamp terminal simultaneouslypressed into positive electrical engagement with a resilientlydepressible contact element carried by and disposed in said insulatingbody.

13. In combination, a prefocus type projection lamp or similar devicehaving a generally cylindrical base provided with an axially-extendingplug member of non-circular cross-section and a plurality ofradially-spaced laterally-extending pins, and a socket comprising a bodyof insulating material open and contoured at one end to 12 freelyaccommodate said base and registerably and freely receive said plugmember and pins and define a reference plane for said lamp, and arotatable locking member secured to the open end of said insulating bodyand movable between open and closed positions about the axis thereof,said locking member having a handle portion and a ring portion, saidring portion having substantially the same diameter as and beingcoaxially aligned with the open end of said insulating body and adaptedthereby to permit the passage of said base, a plurality of pairedfinger-like elements and slots 'in the inner periphery of said ringportion and radially-spaced therealong to permit the passage of saidpins when said locking member is in its open position and to engage saidpins in cam-like fashion when said locking member is subsequentlyshifted to its closed position, said lamp being inserted into saidinsulating body and said locking member being disposed in its closedposition, whereby said lamp is forcibly depressed axially into saidinsulating body and simultaneously seated thereagainst and locked inpredetermined relation axially with said socket.

14. In combination, a projection type electric lamp or similar devicecontaining a concentrated light source and having a basal end portionprovided with a grippable element that is disposed in predeterminedangular relation with respect to said concentrated light source, and asocket comprising a body member interiorly contoured at one end tofreely receive the basal end portion of said lamp and define a referenceplane therefor, said body member having a recess in its inner peripheralwall extending axially inward from its lamp-receiving end and adapted tofreely and registerably receive said grippable element and define a stoptherefor that is located at a predetermined point on the periphery ofthe lamp-receiving end of said body member, a movable locking membercarried by said body member that is rotatable about the axis thereof anddisposed when actuated to engage said grippable element in cam-likefashion and thereby simultaneously apply a torque and an axial thrust tosaid lamp, said lamp being inserted into said body member and saidlocking member being actuated and in cam engagement with said grippableelement, whereby the basal end portion of said lamp and grippableelement thereat are forcibly'seated, respectively, against the portionsof said body member that define the aforesaid reference plane and stop,and said lamp is releasably locked in predetermined relation bothaxially and angularly with said socket.

References Cited in the file of this patent UNITED STATES PATENTS GreatBritain June 27, 1949

